NASA first detailed the DART mission back in February, but at that point, it hadn't picked a partner yet. The DART Project office is located at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, and is managed by the Planetary Missions Program Office at Marshall Space Flight Center in Huntsville, Alabama, for NASAs Planetary Defense Coordination Office in Washington.
The best way to prepare for deflecting an asteroid is to do a test run, which is exactly what NASA has planned for its Double Asteroid Redirection Test (DART).
If successful, the rocket would steer the asteroid away from the Earth's orbital path, avoiding the need for an Armageddon sequel, presumably. The target in question is called Didymos B, and it's the smaller asteroid of the two Didymos asteroids. For larger asteroids, that figure could balloon to 20 years, or several decades for the largest rocks, measuring hundreds of kilometers in diameter. But the stakes are still high: Failure could derail NASA's so-called "kinectic impactor technique", success will provide the crucial data that will inform its deployment against an actual asteroid on a collision course with Earth. In June of 2021 though, we'll be one step closer to finding out.
DART will intercept Didymos B in October 2022, but before then the agency needs to plan every stage of the mission including the launch.
DART is created to intercept a small moon of the asteroid Didymos in late 2022 when the rock comes within 6.8 million miles (11 million kilometers) of Earth.